The present technique relates to a solid-state imaging device, and an electronic system. In particular, the present technique relates to a solid-state imaging device capable of enlarging a dynamic range without deteriorating an image quality, and an electronic system.
Techniques related to an image sensor having two FD capacitances in a pixel section have been proposed in order to obtain image signals having different dynamic ranges using a signal charge in the same storage period (for example, Japanese Unexamined Patent Application Publication No. 2000-165754 or Japanese Patent No. 4502278).
In such an image sensor, electrons stored in a PD are converted into voltages by the individual FD capacitances to be read.
For example, in the technique in Japanese Patent No. 4502278, a modulated presaturated charge signal (S1′)+a modulated supersaturated charge signal (S2′)+CFD+CS noise (N2), and CFD+CS noise (N2) are input into a differential amplifier DC. The difference between these is calculated to cancel CFD+CS noise (N2). And further, an adjustment is made to have the same gain as a presaturated charge signal (S1) by restoration with an amplifier AP using a capacitance ratio of CFD to CS so that the sum (S1+S2) of the presaturated charge signal and the supersaturated charge signal is obtained.
Before the signal S1′+S2′+N2 and the signal N2 are input into the differential amplifier DC 2, the signal S1′+S2′+N2 and the signal N2 may be digitized by A/D converters ADC that are disposed as necessary. Alternatively, the analog signal may be directly input into the differential amplifier DC without disposing the ADC.
Using such a technique, it is possible to enlarge a dynamic range of an image sensor.